1. Field of the Invention
The present invention relates to an improvement of the ski boot which forms the object of French Patent Application Publication No. 2,567,374, the disclosure of which is also incorporated by reference, and corresponding U.S. Application Ser. No. 06/748,458, both of which relate to an apparatus for automatically distributing the tightening forces of the upper with respect to the retention forces of the foot in the shell base without any other manipulation than the closure of the boot.
2. Description of Background and Relevant Information
The ski boot described in the above application includes means for closing portions of the boot constituting the upper on the lower leg of the foot and means for retaining the foot in the shell base, both of which are simultaneously associated with a tensioning element by means of at least one traction element connected to a movable linkage apparatus which is provided with a return member and which is connected to another traction element. As explained and shown, the movable linkage apparatus makes it possible to distribute and transmit the tension force applied on one of the traction elements to the strands of the first mentioned traction element. Furthermore, it is taught that only one of the strands of this other traction element activates an internal foot retention system.
This apparatus is entirely satisfactory with respect to the technical result obtained, in particular for the distribution of forces. It has, however, been seen that the internal retention of the foot by means of an anatomical distribution plate corresponding substantially to the shape of the foot, and pressurized on the foot by one of the strands of the traction element which extends around the return of the movable linkage apparatus, still does not optimally retain the foot, particularly because of the different morphologies of the feet of different skiers. Furthermore, the use of a single traction element to act on the anatomical plate does not make it possible, if desired, to activate another pressure zone on the foot, such as the front of the foot and/or the upper portion of the instep which corresponds to the tibial support of the lower leg.